Receive the latest national-international updates in your inbox

The candidates are preparing for the Denver debates while still doing a bit of campaigning. (Published Tuesday, Oct. 2, 2012)

Like boxers going a few more rounds with sparring partners, President Barack Obama and Republican Mitt Romney are each spending the hours before their Oct. 3 debate going toe-to-toe with a stand-in for their opponent.

And, much like a prize-fighter, each candidate is focusing on three goals for the Denver matchup: anticipating his rival's blows, preparing his own offensive, and practicing how to keep cool under the glare of millions of people, political analysts say.

"The opponent gets into the candidate’s face, gets into his head, to make him feel like he’s really there," veteran Democratic strategist Steve Elmendorf said. "The goal is to practice some real lines and real lines of attack that you think are going to come.”

Election 2012: A Look Back

Republican strategist Brett O'Donnell, who helped Romney prepare for his early primary debates, calls it "live fire practice," and it doesn't stop with the sparring partner. It includes reconstructing a set down to every detail, including the size of the podium and the hot television lights.

"It's basically toughening them up, saying, 'Here's what your'e going to face and here's the worst you could possibly feel and here's how you handle it,'" O'Donnell said.

Obama, whose day job has cut into his practice time, has holed himself up in a hotel outside of Las Vegas with Massachusetts Sen. and former presidential candidate John Kerry playing Romney.

Neither side will say what goes on at those rehearsals - Obama aides have only said that they're trying to get the president to shorten his responses, while Romney has joked about how tough Portman has been on him. But political scientists and party strategists offered glimpses of what they’ve seen in the past.

“It’s quite an elaborate process, a very time-consuming process,” said Alan Schroeder, a journalism professor at Northeastern University who has interviewed participants as part of his research of presidential debates.

Kerry and Portman have likely immersed themselves in their roles by studying a massive briefing book detailing the opponent’s positions and past statements, and by watching videos of past performances, Schroeder said. Each actor tries to immerse himself in the role so he can mimic his subject down to body language and attack style.

“They do a full dress rehearsal with the stage laid out,” Schroeder said. “They videotape those mock debates and critique them.”

Aides try to get candidates accustomed to having someone trying to get under their skin, and practice techniques to remain calm and prevent falling victim to a “gotcha” moment that could be used as campaign fodder later on.

“They practice the opening, and the closing, but the most important parts are anticipating attacks from the other side and preparing to launch an effective offense and defense,” Republican strategist Ron Bonjean said.